Golf swing practice device



March 3, 1970 u s I 3,498,616

GOLF SWING .PRACTICE DEVICE f INVEN'I'OR. 4 4 floaaerfi, #11257 ii 1WM,%

United States Patent 3,498,616 GOLF SWING PRACTICE DEVICE Robert D.Hurst, 4928 Bluebell, North Hollywood, Calif. 91607 Filed Aug. 19, 1968,Ser. No. 753,554 Int. Cl. A63b 69/36 U.S. Cl. 273186 8 Claims ABSTRACTOF THE DISCLOSURE A golf club attachment of elongated tubularconfiguration provided with a spaced pair of attachment clips, thetubular member being divided into a pair of axially aligned chambers,one of which contains a ball or the like adapted to move freely andunimpeded in response to centrifugal and gravity forces, the otherchamber containing a ball or the like that is normally held at one endof the chamber by magnetic means until suflicient centrifugal force isimparted to the ball by swinging of the club to which the attachment ismounted, the elements of the attachment cooperating to produce audiblesignals indicative of a proper backswing, stroke and follow through inresponse to a proper co-ordination of movements by the user. A sounddampening member, made from a material such as cork, is provided on oneend of the chamber in which the ball is adapted to move freely andunimpeded. The chamber ends adapted to produce audible signals mayinclude a sound amplifying tube. The device 'is adapted to be readilydisassembled and reassembled to facilitate replacement of the balls withothers of different diameters and masses, which others may be stored ina hollow plug secured to an end of the attachment.

BACKGROUND OF THE INVENTION The present invention relates to golfpractice devices and particularly an attachment for woods or irons thatis re sponsive to the swing of the club to produce audible signals for aproper co-ordination of backswing, downswing and follow through.

A variety of devices have heretofore been devised and have come into useto aid golfers in the practice of their swings. Commonly, these take theform of an elongated chamber equipped at one end with magnetic or othermeans for retaining a ball, striker, clicker or the like in place at anupper end of the chamber, the holding force being overcome only uponsuflicient centrifugal force being imparted :by the swing of the club todislodge the signalling element into contact with an anvil or the likeat the other end of the chamber. By and large, such devices are of arelatively expensive construction. More importantly, however, theseprior devices are incapable of functioning in all phases of the swing toproduce signals which are useful in indicating when the user has aproper backswing and follow through as well as a proper downswing. Theprior devices are thus of limited utility since they are adapted tofunction only to produce a signal theoretically corresponding to acorrect address of the club face against a ball at the moment of impactonly. So far as I am aware, no prior worker has addressed himself to theproblem of providing a golf club attachment of an inexpensive naturehaving a combination of functionally interrelated elements producingsignals audible to the golfer to aid him in achieving a proper backswingand follow through as well as downswing.

SUMMARY OF THE INVENTION The present invention achieves a simple,relatively inexpensive attachment for golf clubs, which may be eitherwoods or iron, and including interchangeable combinations of magnets andstriking balls by means of which the holding force for the ball may bealtered to accommodate lady or men golfers, or golfers of different orvarying abilities, or the same golfer as he increases his skill. Thedevice comprises an elongated tubular member divided into a pair ofaxially aligned chambers, one of the chambers containing a holdingmagnet normally retaining a signal ball or the like in place. The otherchamber also contains at least one signalling ball that is freelymovable longitudinally of the chamber, the latter chamber being providedat one end with a sound-dampening means so as to not produce any signalupon the ball coming into contact therewith. The plug or other meansdefining an end of one or more of the chambers may be hollow to providea storage capacity for alternatively usable signalling balls having'masses and sizes different from one another or from the balls utilizedwithin the chambers. Another plug or the like defining an end of achamber may be provided at opposite ends with magnets of varyingstrength. With this arrangement, a large number of possible combinationsof magnet and ball are available to the golfer. The double chambercombination may include sound-amplifying means and the signallingelements contained therein are adapted to produce clearly audiblesignals in response not only to the velocity with which the club isswung, but also as a function of the plane or planes through which theclub is swung in the backswing and in the follow through. A properco-ordination of backswing, downswing and follow through producesaudible signals to the golfer marking the top of the backswing, thetheoretical moment of impact and proper completion of the followthrough.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a schematic view showingone form of my invention attached to a golf club and its manner of use;

FIGURE 2 is a longitudinal sectional view of the device, the view beingdisposed in an attitude at least approximately corresponding to theextreme backswing position;

FIGURE 3 is a view similar to FIGURE 2 but showing the relative positionof the elements at the theoretical moment of impact of the club facewith the ball;

FIGURE 4 is a sectional view on the line 44 of FIG- URE 3;

FIGURE 5 is a view similar to FIGURES 2 and 3 but showing the attachmentor device in an attitude approximately corresponding to completion ofthe follow through;

FIGURE 6 is a three-quarter front perspective'view of a golferindicating his backswing, downswing and follow duction of a signal by asecond preferred embodiment of the invention;

FIGURE 7 is a longitudinal sectional view of the second embodiment, thedevice being positioned in an attitude approximately corresponding tocompletion of the backswing;

FIGURE 8 is a view similar to FIGURE 7 but with the device beingpositioned in a vertical attitude such as at 1the moment of theoreticalimpact of club face with the FIGURE 9 is a view similar to FIGURES 7 and8 but with the device positioned in an attitude approximating completionof the follow through; and

FIGURE 10 is a transverse sectional view showing details of anattachment clamp.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment illustrated inFIGURES 1 through 5 is indicated generally by the numeral 10. Thisembodiment includes an upper end plug 11, an upper tube 12, a medianplug 13, a lower end tube 14, and a bottom end plug 15, all of which maybe made of a suitable synthetic plastic material and all of which arearranged in coaxial alignment. While the plugs 11, 13 and 15 may be ofan opaque material, the tubes 12 and 14 are preferably, although notnecessarily, of a transparent material whereby the user may determine ata glance the identity of the particular magnets and balls being utilizedat the moment.

The upper end plug 11 is formed at its opposite ends with coaxialthreaded extensions 16 and 17, each adapted for threaded engagement witha tapped upper end 18 of upper tube 12. As is best shown in FIGURE 2,each of the threaded extensions 16 and 17 terminates in a fiat face inwhich there is fixedly secured one of a pair of magnets 19 and 20. Thesemagnets are of different flux strength and either may optionally bedisposed within the upper end of the tube 12 by connecting either one orthe other of the threaded ends 16 and 17 within the tapped upper end 18of the sleeve 12. As is also shown in FIG- URE 2, a threaded cap 21 ofmetal or other suitable material and formed with internal screw threadsmay be secured over the one of the threaded end 16 and 17 which is notin use thus preventing contamination and corrosion of the non-usedmagnet.

The median plug 13 is also formed at opposite ends with a pair ofthreaded extensions 22 and 23, the former of which is threadedly engagedwith a tapped lower end portion 24 of the upper tube 12 and the latterof which is threadedly engaged in a tapped upper end of the lower tube14. The lower end of the lower tube 14 is also interiorly tapped, asindicated at 26, to threadedly receive a threaded end of the bottom plug15. As is shown in FIGURE 2, the bottom plug 15 is hollow thus defininga pocket 28 that is normally closed by a plug 29 made of cork or othercushioning material that is disposed within the lower end of the lowertube 14.

As is shown in FIGURE 2, a ball 30 is disposed within the upper tube 12,ball 31 is disposed in the lower tube 14, and a pair of balls 32 and 33are disposed within the pocket 28 of the bottom end plug 15. Each ofthese balls is of a different mass than any of the other balls. Sinceall of the parts of the device can be disassembled from one another, itwill readily be apparent that the user may dispose any one of the balls30, 31, 32 and 33 within either one of the chambers defined within thetubes 12 and 14 and the particular ball put into the upper tube 12 maybe used with either one of the magnets 19 and 20 carried by the upperend plug 11.

Referring to FIGURE 1, there is schematically indicated a golfer holdinga club, in this case an iron, having a shank 35 to which the device 10is secured by means of a pair of spring clips 36, the device beingsecured to the club shank adjacent the club head and with the lower tube14 adjacent the club head. Referring to FIGURE 4, it will be seen thateach of the clips 36, which are preferably of metal, is generallyS-shaped having a smaller diameter portion 37 adapted to clamp aroundthe club shank 35 and having a larger diameter portion 38 adapted toclamp around the upper end plug 11 or the lower end plug 15, as the casemay be. The pair of clamps 36 may of course be positioned at otherplaces lengthwise of the device 10 but their location at the oppositeend plugs 11 and is preferred since such positions avoid dampening ofthe signals produced by the movement of the balls within the device.

FIGURES 7 through 10 show an alternative embodiment 50 which ispresently conceived to be the best mode of putting the invention intouse. The device 50 comprises a pair of tubes 51 and 52, a pair of endcaps 53 and 54, and a median plug 55. While the pair of tubes 51 and 52and the end plugs 53 and 54 are identified by different numerals forconvenient identification, it will be seen that the tubes are identicalto one another, as are the end plugs, thus reducing the number ofdifferent parts entailed in the manufacture of the device. The parts,however, have been differently numbered for convenience of description,particularly with reference to the location of parts at upper or lowerends.

Referring to FIGURE 8, the median plug 55 has threaded opposite endportions 56 and 57, each terminating in a preferably fiat end face inwhich there is mounted one of a pair of magnets 58 and 59. The magnets58 and 59 are of different flux strengths, the magnet 59, for example,being weaker than the magnet 58. In order to identify to the user therelative strength of the magnets, the exterior cylindrical surface ofthe median plug 55 is provided with indicia 60, here taking the form ofthe numbers 1 and 2, the number 1 indicating the weaker magnet. In theparticular orientation of parts shown, the threaded end 56 of the medianplug 55 bearing the stronger magnet adjacent the numeral 2 is threadedlyengaged with an adjacent tapped end 61 of the tube 52, opposite ends ofboth the tubes 52 and 51 being thus formed with a tapped end 61. It willbe understood that all threaded connections have the same thread sizeand, accordingly, the opposite end plugs 53 and 54 are similarlythreadedly engaged with corresponding ends of the tubes 51 and 52.

The lower tube 52 contains a ball 65 while a pair of balls 66 and 67 aredisposed within the upper tube 51. As in the case of the previouslydescribed embodiment, the balls 65, 66 and 67 are all different from oneanother as regards their diameter and mass. While the ball 65 in thelower tube 52 is normally held at one end of the tube by the magnet 58,the magnet 59 disposed in the upper tube 51 is provided with anonmetallic hollow cap 68 which surrounds and surmounts the magnet 59thus normally keeping the balls 67, 66 out of contact with the magnet 59and its field.

Referring to FIGURE 8, it will be seen that each of the identical endcaps 53 and 54 is of a hollow counterbored configuration. Thus, theouter ends of each of these plugs has a relatively large diameterchamber 70 whose inner end communicates with a relatively small diameterblind hole 71 terminating against an inner end wall 72 defining one endwall of the chambers within the tubes 51 and 52. This hollowconstruction provides an amplifying chamber at each end of the device 50so as to make more distinctly audible to the user any contact of theballs contained within the device with either one of the walls 72.

In order to mount the device 50 on a golf club, each of the tubes 51 and52 at its opposite ends is formed with a circumferentially extendinggroove 74 so that a clamp 75 may be seated therein. Thus, as is shown inFIGURE 10, the clamp 75 may have a body molded from a single piece of asynthetic plastic material that is bifurcated to define a symmetricalpair of legs 76 that are joined by an integral yoke portion 77. Arelatively large diameter opening 78 is defined in the yoke portion 77of a diameter adapted to seat the clamp in one of the grooves 74 on thetube 51 or the tube 52. The pair of legs 76 are formed with coaxiallyaligned bores 79 and 80, the bore 80 being tapped for threadedlyreceiving the shank of a headed screw fastener 81, the bores beingpositioned adjacent the opening 78. Outwardly from the fastener 81, thepair of legs 76 are formed with a confronting pair of V-block surfaces82 adapted to receive a shank 83 of a golf club 83 therein. As will beapparent, the fastener 81 may be removed thus permitting spreading apartof the pair of legs 76 of the clamp sufficiently to permit a placing orremoving a club shank into and out of the V-block portions 82. Upon thefastener 81 being tightened, both the club shank and the device 50 arefirmly held in place relative to one another. Further, by disposing thepair of clamps 75 within the grooves 74, the device 50 is held againstdisplacement axially relative to the club shank, upon the device beingswung with the club.

The manner of use of the devices and 50 is substantially thesame. Ineither case, of course, the device is first attached to the shank of thegolf club with which the golfer wishes to practice his swing. However,it will be observed that in the case of the device 10, the tube 12 whichcontains the operative bell-magnet combination is disposed uppermostwhile in the case of the device 50, the lower tube 52 containing theoperative ball-magnet combination is disposed lowermost;

Comparing FIGURES 1 and 6, FIGURE l-is a view directly facing the golferon a line normal to the plane of the golfers legs. By contrast, FIGURE 6is a perspective view facing the golfer on a line at about 45 to theplane including the golfers placement of his feet. By comparison ofthese figures, it will be appreciated that the plane or planes throughwhich the club is swung are disposed obliquely with respect to the planeof FIG- URE 1. For a proper appreciation of the mode of operation of myinvention, this obliqueness of the planes through which the club isswung should be borne in mind.

Assuming that the device 10 of the FIGURES 2 through 5 is attached tothe golf club, the sequence of signals emitted by the device is asfollows. First, assuming that the golfer is addressing the ball in theposition 85 of FIGURE 1, the device 10 is positioned in the attitudeindicated in FIGURE 3. Thus, the ball 30 in the upper chamber is in theposition indicated in phantom outline at the upper end of the chamberbeing held in place by the magnet 19. The ball 31 in the lower chamberis resting on the cork 29 at the lower end of the tube 14. Now, as thegolfer moves through his backswing to the backswing position 86 ofFIGURE 1, the device 10 is inverted. As a consequence, the ball 31 inthe tube 14 will drop gravitationally into contact with thecorresponding end of the median plug 13, making an audible sound.However, it will be appreciated that the moment at which the ball 31strikes the median plug 13 to produce this sound is a function not onlyof gravity, but also of the angular velocity with which the club ismoved in the backswing and, further, a function of the obliqueness ofthe plane through which the club is swung during the backswing.Desirably, the club is swung during the backswing in such a plane andwith such speed that the ball 31 does not come into contact with themedian plug 13 until the top of the backswing, i.e., approximately theposition indicated at 86 in FIGURE 1. If the club is taken back toofast, around too flat a plane, the desired click will be delayed or insome cases no click may be produced at all.

In the downswing, if the club is swung with the proper force and thewrists uncocked at the right time, the centrifugal force produced on theball 30 in the upper chamber defined by the upper tube 12 will effectrelease of the ball 30 to travel as indicated by the directional arrowin FIGURE 3 to impact on the corresponding end of the median plug 13 atthe moment theoretically corresponding to impact of the club face withthe ball. This position, of course, also corresponds with the position85 shown in FIGURE 1. At the same time, the ball 31 is thrown downwardlybut as it impacts on the cork 21 no audible click is produced. If thedownswing is properly co-ordinated, the click of the ball 30 on themedian plug 13 will be indicated at the bottom of the swing. If thedownswing is unco-ordinated, this click will be heard either before orafter the bottom of the swing.

In the follow through, while 'the club moves from the position 85 to theposition 87 indicated in FIGURE 1, the moment at which both of the balls30 and 31 return to the opposite ends of their chambers is once againthe function of the plane of the swing as'well as of the arcuatevelocity of the club. At the end of the backswing, the ball 30 will, ofcourse, be in a reset position, firmly held by the magnet 19 again. Themoment at which clicks are produced by the return of the balls 30 and31, if at all, is once again indicative of whether or not the followthrough has been proper. Obviously, if the follow through is abortedbefore the club swings upwardly beyond a substantially horizontalposition, no resetting or clicking sounds of these balls will be heard.On the other hand, if the follow through is proper, the clicking ofthese balls will not be audible until substantially at the moment ofcompletion of a full follow through after the club has progressedupwardly beyond a horizontal attitude. But if a follow through is toofiat, there will be an undue delay in the clicking of the balls.

In the use of the device 50, the sequence of production of signals issubstantially the same. However, I have found that the use of theamplifying chambers defined in the opposite ends of the device makes thesignals produced much more distinctly audible. Further, by positioning.the magnet-ball combination in the lower chamber the ball 65 strikesagainst the sounding wall 72 which directly communicates to theatmosphere through the amplifying chamber.

While I have shown and described two embodiments of the invention, itwill be apparent that variations therefrom may be made by those skilledin the art without departing from the spirit and scope of the followingclaims.

I claim:

1. In a swing-responsive golf practice device, the combinationcomprising:

rigid means defining an axially elongated chamber that is closed by apair of opposite end walls;

a striker element disposed in said chamber having size and shapecharacteristics adapted for free unimpeded movement of said strikerelement in said chamber between said end walls;

the normally upper end wall of said rigid means being adapted to respondto being struck by said striker element to cause an audible sound uponsaid device being inverted, as upon a backswing of said device;

and a sound-dampening means on the inside of the normally lower end wallof said chamber that is adapted to acoustically insulate said lower endwall from contact with said striker element to attenuate sound resultingfrom contact of said striker element with said dampening means, as fromcentrifugal force generated in a downswing of said device.

2. A device as in claim 1 in which:

said rigid means also defines a second, axially elongated chamber thatis closed by a pair of opposite end walls;

and a second striker element is disposed in said second chamber havingsize and shape characteristics adapted for free movement of said secondstriker element in said second chamber between said end walls;

the normally upper endwall of said second chamber mounting a holdingmeans adapted to yieldably retain said second striker element at saidupper end of said second chamber within a predetermined range ofcentrifugal force generated by a downswing of said device;

' the normally lower end of said second chamber being adapted to respondacoustically to being struck by said second striker element when saiddevice is swung with sufficient force to free said second strikerelement from said holding means to throw said second striker elementagainst said lower end wall of said second chamber.

3. A device as in claim 2 in which:

said rigid means comprises a pair of tubes that are detachablyinterconnected by a median plug, the opposite ends of said plug definingan upper end wall of one of said chambers and the lower end wall of theother of said chambers;

the pair of said striker elements being of different masses whereby upondisassembly and reassembly of said tubes and plug, said striker elementsmay be exchanged between said chambers to alter said range ofcentrifugal force.

4. A device as in claim 2 in which:

said rigid means comprises a pair of tubes that are detachablyinterconnected by a median plug, the 0pposite ends of saidplug definingan upper end wall of one of said chambers andthe lower end wall of theother of said chambers;

said median plug mounting a pair of magnets of diflFerent flux strengthson the opposite ends of said plug, whereby upon disassembly andreassembly of said tubes and plugs said plug may be reversely orientedto'alter said range of centrifugal force.

5. A device as in claim 2 in which:

at least one end Wall adapted to respond acoustically to contact by astriker element comprises one endof an amplifier tube Whose other end isopen to the atmosphere.

6. A device as in claim 1 in which:

the end wall adapted to respond acoustically to contact by-a strikerelement comprises one end of an amplifier tube whose other end is opento the atmosphere.

7. A device as in claim 1 in which:

said device is an attachment for a golf club having a spaced pair ofclamp means each adapted at one end for releasably clamping a shank of aclub,

' the other ends'of said pair of clamp means and por- 1 tions of saiddevice contacted thereby being shaped and adapted to .define abutmentmeans preventing relative axial movement of said device and club shaftupon a downswing of said club.

, 8.In a swing-responsive golf practice deviceof the type in which astriker element is movablet in an elongated tubular member to cause asound upon coming into contact with one end wallzof themember, theimprovement comprising: v

a sound-amplifying chamber comprising an amplifier tube having one endopen to the atmosphere and having its other end in communication withsaid end wall of the tubular member.

References Cited UNITED STATES PATENTS

